Hello,

Here is a BIP that matches the reference code that the Segwit2x group has
built and published a week ago.

This BIP and code satisfies the requests of a large part of the Bitcoin
community for a moderate increase in the Bitcoin non-witness block space
coupled with the activation of Segwit.

You can find the BIP draft in the following link:

https://github.com/SergioDemianLerner/BIPs/blob/master/BIP-draft-sergiolerner-segwit2x.mediawiki

Reference source was kindly provided by the Segwit2x group.

Best regards,
 Sergio.